Electronic systems and circuits have made a significant contribution towards the advancement of modern society and are utilized in a number of applications to achieve advantageous results. Numerous electronic technologies such as digital computers, calculators, audio devices, video equipment, and telephone systems have facilitated increased productivity and reduced costs in analyzing and communicating data, ideas and trends in most areas of business, science, education and entertainment. Electronic systems designed to provide these advantageous results typically produce heat as a by product of various processing activities. However, the electronic systems also typically have temperature operation thresholds which if exceeded can cause damage to the electronic systems and/or result in the electronic systems providing unreliable results. Maintaining the temperature of the electronic systems within the thresholds often consumes significant power which can be expensive and also reduce power supply capacity.
Power is consumed by a variety of components within a computer system. Power consumption can be considerable and expensive in centralized computer facilities that operate a large number of computer systems. For example, power consumption is usually a significant portion of operating expenses in a centralized server facility such as a server farm or internet provider.
Another important consideration for a number of computer systems is power supply capacity. Power supply capacity is often limited in a number of computer systems such as portable or mobile computer systems. For example, a number of portable or mobile computer systems operate off limited battery power supplies and even if the batteries are rechargeable it is not always convenient to recharge them. Recharging the batteries typically involves a hard wire connection to a utility power supply and the hard wire connections often tend to reduce the portability advantages of the system. Power consumed by a cooling system including fan operations typically results in less power available for the primary activities of the computer system, such as processing information, displaying results on a monitor, communicating results via a network, etc. The limitations on the power supply capacity tend to increase the significance of impacts associated with power consumed by cooling systems.
Computer systems typically have cooling systems comprising a fan utilized to help provide maintenance of a system temperature. The fan typically blows cool air into ambient spaces around electronic components. The electronic components dissipate heat into the ambient air. The dissipation rate and capacity is proportional to the difference in the temperature of the ambient air and the temperature of the electronic components. Additional cool air flowing into the ambient space of the electronic components pushes out hotter air and permits the electronic components to dissipate greater amounts of heat maintaining a lower temperature. Fan speed is increased to provide additional cool air. Greater amounts of power are consumed as the fan speed is increased.
Power consumed by computer system cooling fans has increased dramatically as cooling demands have increased. The demand for ever more sophisticated and complex computer systems drive development or systems that require additional cooling capacity. The traditional approach of operating fans at a predetermined maximum speed tends to put increased strains and demands on power supplies. The increases can be exponential as fan power consumption is proportional to fan speed raised to the third power. While traditional approaches of operating a fan at a maximum speed can often achieve temperature threshold maintenance it also usually impacts the expense of operating the system and can reduce the capabilities of mobile systems.